1. Enrich and promote the effectiveness of teaching, create more interactions between teachers and students, and make the knowledge better retained. 2. Assist students’ self-study and provide means of previewing and reviewing. Help build up the basic academic level for weaker students. 3. Cooperate with the community and school and provide after-class trainings to support culture-disadvantaged students. 4. Improve the educational conditions of culture-deprived areas, and help solve the special educational inequality between the city and the country. 5. Provide a great solution for the emergent cancellation of class. Reduce the risk of learning discontinuation.